Foam Molding with Moving Plates for Footwear Cushioning

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Solution Overview

Problem

Conventional foam formation methods do not provide optimal performance in terms of cushioning and support, particularly in footwear applications, as they fail to achieve uniformity in the foam structure and often require additional expansion outside the mold.

Innovation Solution

A method involving inserting a foam material into a mold with a top and bottom plate, heating it to expand, and moving one plate relative to the other to cause the foam to fold and form non-uniform, irregular folds, thereby creating a foam component with specific thickness and expansion ratios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional foam formation methods are used, then foam structure uniformity is achieved, but cushioning and support performance is suboptimal

Engineering Contradiction:
Improvecushioning and support performanceVSAvoidfoam structure uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies asymmetry by intentionally creating non-uniform foam structures with varying cell sizes and densities within different regions of the foam. The foam is designed to have a gradient structure where certain areas have larger cells for cushioning while other areas have smaller cells for support, resolving the contradiction between uniformity and performance.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent implements local quality by providing different foam characteristics in different locations. The foam structure is engineered to have region-specific properties where the cell structure, density, and thickness vary locally to optimize both cushioning in impact zones and support in load-bearing areas, thereby achieving optimal performance without requiring complete uniformity throughout.

Inventive Principle:
Principle #3Local quality

2Productivity

If conventional foam formation methods are used, then foam can be formed in mold, but additional expansion outside mold is required

Engineering Contradiction:
Improvefoam formation efficiencyVSAvoidprocess steps
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-configuring the foam material with specific expansion characteristics before molding. The foam is designed to achieve its final desired shape and volume entirely within the mold during the molding process itself, eliminating the need for subsequent expansion operations outside the mold and thereby simplifying the overall process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent merges the expansion and molding operations into a single integrated process. By designing the foam material and molding process to achieve complete formation within the mold, the patent combines what were previously separate steps (molding followed by external expansion) into one unified operation, improving productivity and reducing process complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Shape

If foam is allowed to expand outside mold, then final shape is achieved, but net shape formation within mold is not achieved

Engineering Contradiction:
Improvefinal product shapeVSAvoidnet shape formation
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The patent uses preliminary action by designing the mold and foam material combination to predictably achieve the final desired shape during the molding process itself. The foam's expansion characteristics are pre-engineered to match the mold cavity geometry, ensuring that the foam attains its net shape within the mold without requiring additional forming operations afterward.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies parameter changes by carefully controlling the foam expansion parameters (such as expansion ratio, expansion rate, and timing) to match the mold geometry. By adjusting these parameters, the foam transitions from a raw material state to a precisely formed net shape that directly matches the final product requirements, achieving both shape accuracy and net shape formation in one step.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method produces a foam component with lower stiffness but similar resilience to conventional foams, allowing for a net shape formation within the mold, eliminating the need for further expansion outside the mold and enhancing performance in footwear applications.

Implementation Method 1

heating the foam material to cause the foam material to expand

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

the foam is permitted to expand until the foam cools and takes the shape of the final product

Methodology Applied
Scientific EffectThermal contraction: Thermal Contraction

Data Source

PatentEP3774260B1Foam and method of forming foam
Publication Date: 2024.04.03 NIKE INNOVATE CV
  • EP3774260B1 patent drawingFigure 1~2
  • EP3774260B1 patent drawingFigure 3~4
  • EP3774260B1 patent drawingFigure 5~6

AI summary

A method (40) for making a foam component is provided and includes inserting a foam material (48) into a cavity (68) of a mold (58) having a top plate (60) and a bottom plate (62), heating the foam material (48) to cause the foam material (48) to expand, and moving one of the top plate (60) and the bottom plate (62) relative to the other of the top plate (60) and the bottom plate (62) as the foam material (48) expands and contacts the one of the top plate (60) and the bottom plate (62) to cause the foam material (48) to fold over on itself within the cavity (68).